Alkynylene nitro-dicarbamates



United States Patent 2,978,488 7 ALKYNYLENENITRO-DICARBAMATES Milton B. Frankel, Pasadena, Calif., assignor to Aerojet- General Corporation, Azusa, Calm, a corporation of 2 No Drawing. Filed Jan. 3, 1955, Ser. No. 479,655 16 Claims. (Cl. 260482) wherein R and R are the same or diflerent and are nitroalkyl radicals, and Y is an alkynylene radical;

The compounds of this invention are prepared by condensing nitro-isocyanates with alkyne-diols, in accordance with the general reaction scheme set forth below:

H 0 O H R-NC O+HOYOH-+RI I -OY-O I IR' wherein R, R and Y are as defined above. Nitro dicarbamates which R and R are different are prepared by employing a mixture of isocyanates in the reaction.

As a matter of convenience, the reaction is usually conducted at reflux temperature. Although lower temperatures can be used, the rate of reaction is usually too slow for practical purposes, while at higher temperatures, the reaction is difiicult to control. The reaction is preferably conducted in the presence of a condensation catalyst such as ferric acetylacetonate. Increased smoothness and control of the reaction are achieved when a reaction solvent such as chloroform is used.

The nitro-isocyanates used as starting materials in this invention are prepared by reacting nitro-acid halides with sodium azide and subsequently heating the resultant organic azides under anhydrous conditions to effect their rearrangement to the isocyanates, as disclosed in assignees copending applications Serial No. 405,515, filed January 21, 1954, now Patent No. 2,923,726, and Serial No. 416,386, filed March 15, 1954, now abandoned. The nitro-acid halides are obtained in the conventional manner by reacting a thionyl halide with a nitro-acid, such as 3,3-dinitrobutanoic and 3,3-dinitropentanoic acid. A wide variety of such nitro-acids can be prepared by condensing unsaturated acids, such as acrylic acid, with nitronate salts of alkanes, as described in J. Org. Chem., vol. 16, pp. 161-4, 1951. I

To more clearly illustrate my invention, the following example ispresented. It should be understood, however, that this example is presented merely as a means of illustration, and is not intended to limit the scope of the inven-' tion in any way.

E PLE I l alk l d l a ower yny ene ra rca. Preparation of MN 4:11 (3,3,3-trzmtropropyl)-2-butyne I As a composition of matter N,N, bis(3,33 trinitr 'carbamate '65 propyl)-2-butyne dicarbamate having the structural forp Equivalent quantities of 1,4-butynediol and 3,3,3-trinimula: v

r No, i H 0 0 Y N0. 7

t it t' 8 v No,- -omom- -o-cn;-c=c-cn, -oomcm- -NO tropropyl isocyanate were refluxed with about 1% by weight ferric acetylacetonate for eight hours. The solution was then evaporated to dryness in vacuo, leaving a quantitative yield of a yellow oil, which was identified as N,N-bis(3,3,3-trinitropropyl)-2-butyne dicarbamate.

The ballistic properties of N,N'-bis(3,3,3-trinitropropyl)-2-butyne dicarbamate are as follows:

Calculated lead block value: 111 TNT=100. I Calculated ballistic mortar value: 121 TNT= 100.

As disclosed in my eopending application Serial No."

479,657, filed concurrently with the present application, the N,N' nitrated derivative of the above compound is a solid, M.P. 94-96 0., having an actual heat .of combustion of 1834 caL/gm. a

A wide variety of compounds can be prepared in accordance with the procedure set forth in Example I. N,N'-bis(3,3-dinitrobutyl)-2-butyne dicarbamate is prepared by condensing 1,4-buty'ne-diol with 3,3-dinitrobutyl isocyanate; N,N'-bis(3,3,3-trinitropropyl) -3-hexyne dicarbamate is;prepared by condensing 3-hexyne-1,6-diol with 3,3,3-trinitropropyl isocyanate; and unsymmetrical N-3,3- dinitrobutyl-N-3,3,3 trinitropropyl-Z-butyne dicarbamate is prepared by reacting 2butyne-1,4-diol with a mixture of 3,3 -dinitrobutyl isocyanate and 3,3,3-trinitropropyl isocyanate.

It is apparent that any member of series of alkynylene-nitro-dicarbamates can be prepared by merely condensing the appropriate nitro-isocyanate with an alkyne diol, according to the teachings of thisinvention.

The fvaluable alkynylene nitrmdicarbamates of this, in-

vention readily; undergo nitration, to form valuable high explosives, as disclosed in my co'pending application Serial", No. 479,657, filed concurrently with the present application. The high explosivesthus obtained can be used in any conventional explosive missile, projectile, rocket, or the like, as the main explosive charge. An example. of such a missile is disclosed in United States PatentNo.

2,470,162, issued May 17, 1949. One way of using.

the high explosives of this invention in a device such as that-disclosed in United States Patent No. 2,470,162, is

to pack the crystalline explosive in powder form into the V l warhead of the missile. Alternatively, the crystals can be first pelletized and then packed. A charge thus prepared is sufficiently insensitive to withstand the shock 1 V entailed in the ejection of a shell from a gun barrel or f from a rocket launching tube under the pressure devel oped from ignition of a propellant charge, and can be caused to explode on operation of an impactor time fuse-mechanism firing a detonating explosive such as lead; 'f

azide or mercury fulminate.

I claim:

1. As compositions of matter, alkynylene nitro-dicar bamates having the general formula:

wherein R and R' are lower nitroalkyl radicals and Y is i 'aon as 3 3. As a composition of matter, N,N-bis(3,3-dinitro- 10. The method of claim 9 wherein the reaction is conbuty1)-2-butyne dicarbamate having the structural forducted in the presence of ferric acetylacetonate. mula: 11. The method of preparing N,N-bis(3,3 -dinitrou 1 l i CHI-+CHICHfiN -COCHr-CEG-CHrO--N-CHQCHg-C-CH! N02 NO:

4. As a composition of matter, N,N'-bis(3,3,3-trinitrobutyD-Z-butyne dicarbamate which comprises reacting propyl)-3-hexyne dicarbamate having the structural for- 3,3-dinitrobutyl isocyanate with 1,4-butynediol.

mula: 10 12. The method of claim 11 wherein the reaction is Ne r t i e i NOr-C-CHzCHz--N-C0-CHzCHr-CEC-GH1CH1OC-NCHaCHr-(?-N0:

N0: N0: 5. As a composition of matter, N'-3,3-dinitrobutyl-N- conducted in the presence of ferric acetylacetonate. 3,3,3 -trinitropropyl-2-butyne dicarbamate having the 13. The method of preparing N,N-bis(3,3,3-trinitrostructural formula: propyl)-3-hexyne dicarbarnate which comprises reacting NO: 111 (a h) EI NO: CH -(J-CHgCHpN-C-O-CH:-CEC-CHr-0-C-N- OH CIIz-(i-NO;

N03 N01 6. The method of preparing alkynylene nitro-dicar- 3,3,3-trinitropropyl isocyanate with 3-hexyne-l,6-diol. bamates having the general formula: 14. The method of claim 13 wherein the reaction is H O 0 H 5 conducted in the presence of ferric acetylacetonate. 1 ll ll 1 15. The method of preparing N-3,3-dinitrobutyl-N- R NC .O Y0 CN 1? 3,3,3 trinitropropyl 2 butyne dicarbamate which comwhich OOIIIPI'ISCS. reacting a mtro-contalmng isocy n prises reacting 1,4-butynediol with a mixture of 3,3,3-triwith an alkyne diol havlng the general formula: nitropropyl isocyanate and 3,3-dinitrobutyl isocyanate.

30 16. The method of claim 15 wherein the reaction is conducted in the presence of ferric acetylacetonate. wherein R and R are lower mtroalkyl radicals and Y is a lower alkynylene radical. References Cited in the file of this patent 7. The method of claim 6 wherein the reaction is con- UNITED STATES PATENTS ducted in the presence of ferric acetylacetonate. 35 2'703810 ward Mar. 8, 1955 8. The method of claim 7 wherein the reaction is conducted in the presence of an inert solvent. OTHER REFERENCES The method of p p g P Gaylord: Journal of Organic Chemistry, volume 20, pyl)-2-hutyne dicarbamate which comprises reacting 333- No. 4, pages 546-548 (1955); received for publication trinitropropyl isocyanate with Z-butynediol. Dec. 22, 1954. 

1. AS COMPOSITIONS OF MATTER, ALKYNYLENE NITRO-DICARBAMATES HAVING THE GENERAL FORMULA: 